Engine



P. L. SCOTT Jame 30, 1936.

ENGINE Filed Aug. 3, 1931 Patented June 30, 1936 UNITED STATES PATENT OFFICE 7 Claims.

My invention relates to an improved method and apparatus for atomizlng, mixing and burning liquid fuel. It is adapted to engines of the internal combustion type, particularly those operating on the Diesel cycle, or in general by the injection of fuel with or without compression ignition.

One object of my invention is to provide a method of positively atomizing fuel and simultaneously mixing the atomized fuel with air. Another object of the invention is to provide for sufficient atomization and mixture in a positive manner, particularly with respect to the mixing process. Another object of my invention is to provide a simple arrangement of atomizing and mixing apparatus of such form as to promote very high output for a given volume of combustion space together with good fuel consumption.

Other objects will appear from time to time during the course of the specifications and claims.

For the purpose of illustration, a two-cycle single acting Diesel engine is shown with the apparatus, which is the subject of my invention, applied thereto. While this is an entirely operable and suitable construction it will be understood that the system may be applied to a wide variety of engines and even to other combustion apparatus without departing from the spirit of I the invention.

The drawing shows an elevation in section of an engine together with the atomizlng and mixmg apparatus;

A is a crank case in which is journaled a crank shaft A which is driven by connecting rod A acting on a crank pin A A is a piston carried on the end of the connecting rod opposite the crank. This apparatus forms conventional reciprocating engine structure.

B is a cylinder having an exhaust port B and an air scavenging and supply port B Air is supplied to the port 13 by any method commonly used in engines of this type, and is not shown since it forms no essential part of the invention. B is a cylinder head having a water jacket B. B is a main combustion space formed within the cylinder head B B is an air duct or nozzle designed to convey air with a minimum friction loss toward the main chamber B. B" is a restriction between the air passage 1? and the chamber B which may or may not form a part of'the structure.

r C is a cylinder containing within it a piston C and joined to the duct B by a passage C The piston C is driven by a short rod C a bell crank C and a push rod C The push rod C is guided in an extension 13 of the cylinder head B The push rod C is in turn driven by a cam C mounted on a lay shaft which shaft is driven from the engine crank shaft by the gear train C C C D is a fuel atomizing valve positioned with its nozzle or tip D at the entrance to the combustion chamber B This valve is supplied with liquid fuel under suitable pressure through a pipe D and fuel pump D which may be of any form commonly used with such engines. This pump is driven by the gear D from the gear C It receives fuel through the fuel inlet pipe D in any conventional manner.

The use and operation of my invention isas follows: The engine shown in the drawing is assumed to have conventional air and fuel supply and other customary adjuncts and to be started by any customary means. Upon an up-stroke of the piston, A air is compressed in the usual manner into the combustion space B The compression may be to a point sufficient to ignite fuel atomized through any common form of nozzle D. It is not necessary, however, to carry out the process that compression be raised to the ignition temperature, as the apparatus may be used in conjunction with engines employing electric ignition or hot surfaces. This air under pressure, filling the passages B and C exerts pressure upon the piston C tending to force it outwardly and fill the cylinder C with a portion of the air charge. This outward motion of the piston is permitted through the motion of the driving linkage controlled by the cam C. This cam C is so positioned with relation to the crank shaft A through its train of gears that its return face will permit the auxiliary piston C to recede at some desired time during the compression stroke. At or near the end of the compression themain piston A will be in an upward position, the auxiliary piston will be in an outward position and the compressed air charge will lie partly within the main combustion space E and partly within the cylinder C together with a small quantity in the connecting ducts. The amount of the air charge held in the auxiliary cylinder C will be proportioned, with relation to the main charge, according to the particular requirements of the engine. It is a matter to be determined individually for each separate engine design. With the air charge so divided and the main piston in proper position for the injection of fuel, delivery of fuel is begun by means of the fuel pump D to the valve D, atomization taking place at the nozzle tip D At or about the time the discharge r or atomized i'uel names, iromlthe tip 1: into the combustion space 13 the auxiliary piston C 1 begins a return stroke, forcing substantially all i the air in the cylinder C through the ducts C 1, and B and into the main chamber B This; delivery of air during atomization of the fuel; is for the purpose partly of providing necessary air for combustifrn, and partly to creataa coni trolled air flow of en intensity and direction such as to promote thorough mixing between the fuel and the entire volume of air enclosed within the v combustion space, "To aid in obtaining the desired direction and velocity, a throat B may be provided in which the tip of the fuel valve inay be approximately centered. The question of the quantity of air, its velocity and direction are matters which must be determined for each engine designed. The principle involved is that there shall be a substantial controlled delivery of air at or about the time of injection and substantially in a manner to assist to best advantage the dispersion oi atomized fuel. It will be seen that the auxiliary piston may develop, upon its portion of the air charge, any desired pressure, but in practice the determining factor will. be that there will be only sumoient pressure to promote adequate mixing of the atomized iuelwith the full air charge. It will further be noted that this air supply system is in no wise directly used to atomize the liquid tuel'thoughit may have an indirect additive effect in the process of fuel atomization, The fuel is primarily atomized and delivered to the combustion space by a separate It will be seen that the shape of the combustion chamber, the position of the iuei valve, and

the position of the auxiliary chamber together with the associated driving mechanism may take a very wide variety or forms depending upon the particular requirements oi individual designs without departing irom the spirit oi the invention.

I claim:

1. In an engine, a main cylinder, 9. piston mounted to reciprocate therein, means to operate said piston to compress air therein, a separate and distinct combustion. chamber having comrnunioatlon with the main cylinder, a fuel nozzle positioned to discharge fuel into the combustion chamber, an auxiliary cylinder, means interposed between the auxiliary cylinder and said combustion chamber defining an air nozzle discharging into the combustion chamber,'and means operable to transfer air from the main cylinder to the auxiliary cylinder, said last mentioned means including an auxiliary piston mounted to reciprocate within the auxiliary cylinder, and meam ior reciprocating said aumliary piston to inter= mittently deliver the air from the auxiliary cylinder into the combustion chamber through said air nozzle.

2. In an engine, a main cylinder, a piston mounted to reciprocate therein, means to operate said piston to compress air therein, a separate and distinct combustion chamber having communication with the main cylinder, 9. fuel nozzle positioned to discharge iuel into-the combustion chamber, an auxiliary cylinder, means interposed between the auxiliary cylinder and said combustion chamber defining an air nozzle surrounding the fuel nozzle and discharging into the combustion chamber, and means operable: to transfer air from the main cylinder to the auxiliary cylinder, said last mentions means including an auxiliary piston mounted to reciprocate within the auxiliary cylinder, and for reciprocating said auxiliary piston to intermittent- 1y deliver the air from the auxiliary cylinder into the combustion chamber through said lair nozzle.

3. In an engine, a main cylinder; 9. piston 5 mounted to reciprocate therein, means to operate said piston to compress air therein, a separate and distinct combustion chamber-having communication with the main cylinder, a fuel nozzle positioned to discharge :ruel into the oom- 10 bustion chamber, an auxiliary cylinder, means interposed between the auxiliary cylinder and said combustion chamber-defining an air nozzle discharging into the combustion chamber, said combustion chamber at the point of communica- 15 tion with said air nozzle being formed with a constriction defining a throat surrounding the fuel nozzle, and means operable to transfer air from the main cylinder to the auxiliary cylinder, said last mentioned means including an auxil- 20 iary piston mounted to reciprocate within thee auxiliary cylinder, and means for reciprocating said auxiliary piston to intermittently deliver the air from the auxiliary cylinder into the combustion chamber through said air nozzle. 25

4. hi an engine, a main cylinder, a main piston mounted to reciprocate therein, means for operating said main piston to compress air within the main cylinder, a combustion chamber positioned beyond the confines oi' the main cylinder 30 7 'large cross-sectional area providing communication betweer' the auxiliary cylinder and the combustion chamber whereby to permit the nonturbulent transfer of large quantities of air between the combustion chamber and the auxiliary cylinder, a piston within the auxiliary cylinder and means to reciprocate the same to intermittently deliver the air from the auxiliary cylinder.

5. In an engine, a main cylinder, a main piston mounted to reciprocate therein, means for operating said piston to compress air within the main cylinder, a separate combustion chamber comprising substantially all of the clearance volume of the main cylinder disposed outside the confines of the main cylinder and having tree and open communication with the main cylinder, said combustion chamber being of substantially smaller cram-sectional area than that of the main cylinder, a fuel atomlzing system terminating in an etc-mining nozzle, an auxiliary cylinder of substantial volume with respect to the volume oi the combustion chamber having its axis disposed transvcrsely of the axis 01' the combustion chamber and connected to the combustion chamher by a short ncn-tin'bulent air pasaaga'sald atomizing nozzle extending through said nonturbulent air passage and being positioned to discharge fuel into the combustion chamber, a piston mounted in the auxiliary cylinder and adapted to transfer air back and forth through said air passage, and means for reciprocating the piston in the auxiliary cylinder to remove air from and to deliver the air to the combustion chamber.

6. In an engine, a main cylinder, 9. main piston 7 mounted to reciprocate therein, means for operatlas-said piston to compress air within the main cylinder, a separate combustion chamber comprising substantially all of the olearance'volume oi the main cylinder disposed outside the -con- 75 er cross-sectional area than that of the main cylinder, a fuel atomizing system terminating in an atomizing nozzle, anauxiliary cylinder of substantial volume with respect to the volume of the combustion chamber having its axis disposed transversely of the axis of the combustion chamber and connected to the combustion chamber by a short non-turbulent air passage comprising an extension of the combustion chamber and'disposed substantially coaxialiy thereof, said atomizing nozzle extending through said non-turbulent air passage and being positioned substantially centrally of said passage and substantially axially of said combustion chamber to discharge fuel into the combustion chamber, a piston mounted in the araxliiary cylinder and adapted to" cylinder, a separate and distinct substantially conical combustion chamber comprising substantially all of the clearance space of the main cylinder, said combustion chamber having free and open communication with said main cylinder at substantially the point of maximum cross-sectional area of said combustion chamber, a fuel atomizing system including an atomizing nozzle positioned to discharge fuel into the com-' bustion chamber, an auxiliary cylinder of substantial volume with respect to the volume of the combustion chamber having its axis disposed transversely of the axis of the combustion chamber and connected to the combustion chamber by a short non-turbulent air passage comprising a substantially axial extension of said combustion chamber at the end thereof remote from the main cylinder, said non-turbulent air passage defining an air nozzle surrounding the fuel nozzle,

a piston mounted in the auxiliary cylinder and 20 

